Calculating machine



Patented May 9,1922.

F. A. BELT.

CALCULATING MACHINE.

APPLICATION FILED MAR. 4. 1920.

FRANCIS A. BELT, OF CINCINNATI, OHIO.

CALCULATING MACHINE.

`Specification of Letters Patent.

Patented May 9, 1922.

Application mea March 4, 1920. serial No. 363,155.

Beit known that I, FRANCIS A. BELT, a citizen of the United States, anda resident of the city of Cincinnati, in the county of Hamilton andState of? Ohio, have invented certain new and useful Improvements inCalculating Machines, of whichthe following-is a full, clear, and exactdescription, reference being had to the drawings forming apart'of thisspecification.

invention relates to improvements in calculating machines whereinmovable charts or columns of figures are vused with relation to apermanent column and has as its general object an arrangement of movableand fixed factors which lend themselves to easy, rapid and accuratecalculation.

The exact nature of the numbers or the arrangement of factors whichoccurs in the showing 'of my invention is not essential since thefactors selected for illustration have been chosen merely as a means ofexemplifying the invention residing therein. The example chosen forillustration is 'one wherein the fixed factors run froml l to 100 andare arranged in a column running lengthwise of the exposure opening..forthe movable factors. The movable chart has 100 columns and each columnbegins with a consecutive number from l to 100. There are in each column100 numerals comprising the successive products of multiplication of.the first numerals bly each numeral in a series of from l to 100.

My invention also consists in certain lmarkings on the movable chartwhich greatly facilitate the vspeed and accuracy with which thecalculation can be made.

In the drawing, the figure illustrates a.

lan view of a double box indicator partly Eroken away to show thecharts.

A simple form of mechanism for employing the features of my invention isa box l, which may be in two sections with hinges 2 between them, whichboxes mount spindles 3, 3, on which are pinions`4. These spindles mountrolls 5 which carry the movable charts 6.

The top ofthe box, be there one or more, is formed of ruled cover 7which has a. longitudinal exposure or slot covered with a suitabletransparent material. I-prefer to have running through lengthwise alongthis sheet of transparent material a l1ne of dots 9, or a very lightcontinuous line to serve as decimal points for the numerals on themovable chart.

Extending along one of the edges of the opening will be the series ofnumerals which have been selected as the factors which will beconvenient for the desired calculat1on,|that is to say the calculationsfor which the device is especially arranged.

In this instance we have shown a series of numerals running from l to100. Any other arrangements for quick calculation can be inserted on thecovers either in conjunction with the xed factors or without specialrelation to them.

The movable charts 6 are wound on the rolls 5 and theI rolls 5 lrapidlyturned by means of a pinion `l0 mounted on a spindle 11 and controlledby a hand wheel 12 mountedv exterior of thebox.

In the instance shown the charts 6 are made up of a series of columnsof'numbers, each column having 100 numerals in it whlch are equal to theproduct of the first numeral at the head of the column and the fixedfactor opposite which any one numeral will come during the movement ofthe chart past the .transparent opening in the fixed cover 7.

In the left hand chart 6 shown in the drawing there will be 100 columnsof numerals each column beginning with a consecutive number running from1 to 100. Thus the column which is exposed through the transparencybegins with the lnumeral 40 and the numerals running down the columnfrom the numeral 40 are the result of multiplying 40 bythe numeral onthe chart 6 opposite which any numeral of the movable chart column willcome. Thus opposite the numeral 39 on' the fixed chart will bethenumeral 1560 on the movable column which is the result of multiplying 40by 39. Also the numeral 1600 appears opposite the fixed numeral 40, 1600being the product of 40 multiplied by 40 or in other words the square ofL10.

In order to facilitate working fractions, particularly simple fractions,I find it desirable to print all simple numbers appearing in the variouscolumns in heavier type than the complicated numbers are printed, thusthe numeral 1560 is in small type while 1600 is in large type, being asimple number.

Further due to the fact that the decimals or decimal points are on thetransparent element in the slot of the fixed cover the proper decimalscan be readily arranged for, throughouteach column since thev operatorby arranging the position of the decimal with relation to the firstnumeral in the column will thereby adjust it properly for all numerals'in the column.

IVithout a certain additional feature of the movable chart, it would bemore orless a slow o eration to find the proper product and factorsdesired for a calculation and accordingly I print on the face of themovable chart a series of special indicators or slugs 13. There will beas many of the special indicators as there are factor numbers on thefixed chart.

Since the number of columns of gures in the movable chart will always beequal to the number of numerals in the one column of the fixed chart,the slugs will be printed opposite the product of the number at the headof the column multiplied by itself. This will bring the slugs for eachcolumn opposite the number on the fixed chart which corresponds to thefactor number of the movable chart column.

Thus in the exposed column at the left of the figure of the drawing,will be found an indicator printed opposite the numeral 1600.

At the head of the column will be found the basic number 40, and on thefixed chart. the indicator will point to the numeral 40, therebyindicating that the basic numeral of the column is 40. n

The operator by rapidly twirlingthe operating knob can make the chartmove so quickly as to form a seemingly continuous line of indicatorsrunning downwardly or upwardly of the exposed slot, and since the fixedchart is .not moving, he can Very rapidly arrive at any desired columnof the movable chart, by stopping its movement as soon as the indicatorcomes opposite the number which he desires for a basic number.

On the right hand chart I have shown a different arrangement wherein thebasic numerals are the decimal expression of fractions based ondivisions of the numeral 144/144ths. The fixed numbers run from 1 to100, and are used as the factors of 144 in succession. Thus the basicnumber for the first column of the movable chart is the decimalexpression for 1/144th, and the exposed column in the drawing is60/144ths.

In this second chart, the indicator is printed as before and comesopposite the fixed factor numeral which is the same as the factor of themovable column adjacent to which the indicator is to be found.

Thus in the exposure for the right hand chart, the indicator is printedopposite the number v25, which is the product of 60 times 60/144ths, orthe decimal .4166, said 60/144ths being the factor number of the column.y

This right hand side ofthe device is to be employed in computingproblems'involving feet and inches anddozens and gross and hours,minutes and seconds.

It may also be employed in computing interest in banks which employ thesystem of finding daily interest by dividing the total yearly *sum by360 instead of by 365. The number 36 on the fixed chart will be the keynumber in figuring interest, and the number which comes opposite 36 onthe movable columns, will be the percent per annum, a thousand dollarsdependent upon the decimal position of the chart.

This will be evident upon examination of the example shown on the righthand chart. If any number shows opposite the numeral 36, it is obviously36 or 360 times the basic numeral of the column, and since percents on athousand dollars for one year are mere decimal expressions, of theinterest factor itself, the operator can readily bring opposite thenumber 36 the number which is at one and the same time, both theexpression of the product of a thousand dollars times the interestdesired and also the rate of interest itself. Thus on the chart in thedrawing, fifteen per cent on a thousand dollars for a year would bringin 315.4166 per day.

lVith .4166 at the head of the column, the product of any number up to100 by it will give total of the interest for that many days, fortwenty-four days the total at fifteen per cent would be $10.00. Intereston $6000 at fifteen per cent for one day would `be $2.50.

Should it be desired to work at 365 days per year then the right handchart will readily adapt itself to the calculation although not to -morethan two decimals, with absolute accuracy.

It can readily be understood that to ref' duce interest at 360 days tointerest at 365 days, the resulting sum for 360 days should be reducedby one seventy-third of the total. My chart will work in 72nds, (onehalf of 144) and after the sum per day is calculated, thelopera-tor willturn to the second column of the movable chart (or 2/144ths) to find theproper subtrahend.

The right hand chart is better for interest calculation than the lefthand because it is figured out to a decimal which includes fac tors ofthe number 12, the same being also a factor of 360.

By reading on the left hand chart, for example it can be seen that ifthe interest otn one vthousand dollars is $144.00 per annum, i. e., atthe rate of 14.40%, then the daily interest will be 40 cents.

But it would be impossible to bring a numeral 15 opposite the 36 mark onthe fixed chart at the left, because the basic numerals of none of thecolumns when multipliedby 36 would give 15.

The above examples, as have been statedf are merely those selected forillustration, as great many different arrangements would be possible fordifferent sorts of work.

As has bee'n said I do not desire to limit myself to any one specialform of calculation or arrangement of fixed factors. My invention isessentially one involving certain basic principles which may be adaptedto a wide number of uses. Having thus described my invention, what Iclaim as new and desire to secure by Letters Patent is 1..;[n acalculating machine, the combination with a housing, a chart mountedtherein upon suitable rollers having transverse columns of numerals,said housing having an'e'longated opening to expose vthe transversecolumns on the chart, a seriesvof numerals arranged along the opening,each numeral of said series having special relation to one of thecolumns on the chart, and a 'special indication device on each column onthe chart adapted to come oppositev the numeral having special relationto said column, whereby the operator may rapidly move the chart andwatch the special numeral for the desired column until an indicatorcomes opposite. it.

2L In a calculating machine, the combination with a housing, a chartmounted therein upon suitable rollers having transverse columns ofnumerals, said housing having an elongated opening to expose thetransverse columns on the chart, aseries of numerals arranged along theopening, each numeral of said series having special relation to one ofthe columns on the chart, and a special indication device on each columnon the chart adapted to come opposite the numeral having specialrelation to said column, whereby the operator may rapidly move the chartand watch the special numeral for the desired column until an indicatorcomes opposite it, said series of numerals and columns arranged inregular order,- so that the operators view of the chart through the slotwill be'of a traveling line formed by the indicators as they iiashacross the slot.

3. In a calculating machine, the' combination wi-th a housing, a chartmounted therein on suitable rollers having transverse columnsofpnumerals, said houslng having an elongated opening to expose thetransverse:

columns on the chart, a series of numerals located along the opening andarranged for coincidence with numerals of the columns, and a transparentdecimal marker extending over' said slot and having points arranged inline with the'numerals in said columns, whereby displacement ofthe chartby one space Will result in a shift of the points in common to allnumerals on the column of the chart exposed at the time of the shift.FRANCIS A. BELT.

